배열 요소 null, array_replace

https://www.postgresql.org/docs/current/functions-array.html#ARRAY-FUNCTIONS-TABLE

 

array_length ( anyarray, integer ) → integer

Returns the length of the requested array dimension. (Produces NULL instead of 0 for empty or missing array dimensions.)

array_length(array[1,2,3], 1) → 3

array_length(array[]::int[], 1) → NULL

array_length(array['text'], 2) → NULL

 

array_replace ( anycompatiblearray, anycompatible, anycompatible ) → anycompatiblearray

Replaces each array element equal to the second argument with the third argument.

array_replace(ARRAY[1,2,5,4], 5, 3) → {1,2,3,4}

update tb_player set point = array_replace( point, null, 0 ) where array_length( point, 1 ) != 17

참조 : https://stackoverflow.com/questions/31108946/postgres-returns-null-instead-of-for-array-agg-of-join-table/33145722